Chewing on a piece of lemon or even a bit of lemon peel is an effective way to enhance the production of saliva in a dry mouth. The saliva flushes out the bacteria causing bad breath.
Note: Grind dry lemon peel into a fine powder. Whenever you brush, mix lemon peel powder and water to make a paste. Use this paste to brush your teeth normally.
Adding a squirt of lemon juice to any tea of your choice helps to enhance its flavor and refresh your breath.